CNAME records having MX

[Michael Kjorling]

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Actually you are thinking the wrong way around here... or at least
that's how I interpreted the question. Let's take a look at what you
did NOT quote:

> > A CNAME can point to an MX, that is fine.
>
> nope.

I'd interpret this as something on the order of:

	foo.com. MX 10 bar.foo.com.
	bar.foo.com. A 123.45.67.89
	baz.foo.com. CNAME bar.foo.com.

Which is perfectly legal, unless someone changed that recently. If
they did, I am in major trouble as I am doing exactly that myself in a
couple dozen zones, and I bet there are people doing this for bigger
setups as well.

I agree that it is not allowed to point a MX RR *at* a CNAME RR,
though; like this:

	foo.com. MX 10 bar.foo.com.
	bar.foo.com. CNAME baz.foo.com.
	baz.foo.com. A 123.45.67.89

But that was never the question in this case.


Michael Kjörling


On Dec 14 2001 18:16 -0500, Joseph S D Yao wrote:

> On Sat, Dec 15, 2001 at 12:04:57AM +0100, Michael Kjorling wrote:
> ...
> > Why not? A properly defined MX is just an A RR, and a CNAME should
> > point to an A RR.
> >
> > Where is the problem in that?
> >
> > How you happen to be using the record is nothing BIND really cares
> > about.
> ...
>
> (*sigh*)
>
> FAQ.  Frequently ANSWERED question.
>
> RFC2181 #10.3:
>
>    The domain name used as the value of a NS resource record, or part of
>    the value of a MX resource record must not be an alias.  Not only is

- -- 
Michael Kjörling  --  Programmer/Network administrator  ^..^
Internet: michael at kjorling.com -- FidoNet: 2:204/254.4   \/
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"There is something to be said about not trying to be glamorous
and popular and cool. Just be real -- and life will be real."
(Joyce Sequichie Hifler, September 13 2001, www.hifler.com)
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